London, Aug 28 (IANS): Men who eat tomatoes over ten portions a week have an 18 percent lower risk of developing prostate cancer, new research shows.

To reach this conclusion, researchers at the universities of Bristol, Cambridge and Oxford looked at the diets and lifestyle of 1,806 men aged between 50 and 69 years with prostate cancer and compared it with 12,005 cancer-free men.

The study developed a prostate cancer 'dietary index' which consists of dietary components - selenium, calcium and foods rich in lycopene - that have been linked to prostate cancer.

It found that men who had optimal intake of these three dietary components had a lower risk of prostate cancer.

Tomatoes and its products - such as tomato juice and baked beans - were shown to be most beneficial, with an 18 percent reduction in risk found in men eating over 10 portions a week.

"This is thought to be due to lycopene - an antioxidant which fights off toxins that can cause DNA and cell damage," said Vanessa Er from the school of social and community medicine at the University of Bristol.

"Tomatoes may be important in prostate cancer prevention. However, further studies need to be conducted. Men should still eat a wide variety of fruits and vegetables, maintain a healthy weight and stay active," she added.

The paper appeared in the medical journal Cancer Epidemiology.